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Attach, read and remove the structures of a frame

Source: R/structure.R
structures.Rd

[Experimental]

A frame can carry any number of named anistructure()s, each spanning the levels of one identity or temporal variable. Several may span the same variable and overlap: a football frame can hold team, defence and left_flank over individual alongside a skeleton over keypoint. A structure's points are its members; levels it does not list are outside it.

  • set_structure() attaches a structure under name, replacing one of the same name.

  • get_structure() returns all structures as a named list, or one.

  • remove_structure() drops one.

Points not found in the data are kept with a warning, in case they are recorded in another file.

Usage

set_structure(data, structure, variable = "keypoint", name = variable)

get_structure(data, name = NULL)

remove_structure(data, name)

Arguments

data

An anipoint.

structure

An anistructure().

variable

The what or when key whose levels the points are.

name

Name to store the structure under. Defaults to variable.

Value

set_structure() and remove_structure(): data, with the structures updated. get_structure(): a named list of structures, or one structure.

See also

anistructure()

Examples

af <- example_anipoint(n_obs = 3, n_individuals = 2)
af <- set_structure(af, example_structure())
get_structure(af, "keypoint")
#> <anistructure> 11 points, 10 segments, 3 joints
#> variable: keypoint; root: abdomen
#> Points: abdomen, neck, hip_right, hip_left, knee_right, knee_left, head,
#>   shoulder_right, shoulder_left, foot_right, foot_left
#> Segments: spine: abdomen - neck, head: neck - head,
#>   shoulder_right: neck - shoulder_right, shoulder_left: neck - shoulder_left,
#>   hip_right: abdomen - hip_right, hip_left: abdomen - hip_left,
#>   thigh_right: hip_right - knee_right, thigh_left: hip_left - knee_left,
#>   shin_right: knee_right - foot_right, shin_left: knee_left - foot_left
#> Joints: neck: spine - head, knee_right: thigh_right - shin_right,
#>   knee_left: thigh_left - shin_left

# Several structures over the same variable
af <- af |>
  set_structure(anistructure(points = c("1", "2")), "individual", "pair") |>
  set_structure(anistructure(points = "1"), "individual", "focal")
names(get_structure(af))
#> [1] "keypoint" "pair"     "focal"